Re: [PATCH v3 1/2] dt-bindings: hwmon: amc6821: add fan and PWM output

[Rob Herring <robh@kernel.org>]

On Tue, Apr 01, 2025 at 08:13:14AM +0200, Krzysztof Kozlowski wrote:
> On Mon, Mar 31, 2025 at 05:52:28PM +0200, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > Add properties to describe the fan and the PWM controller output.
> > 
> > Link: https://www.ti.com/lit/gpn/amc6821
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> > v3:
> >  - explicitly describe the fan, use standard PWM and FAN bindings
> >  - pwm.yaml cannot be referenced, because of the $nodename pattern that is
> >    enforced there
> > v2: https://lore.kernel.org/all/20250224180801.128685-2-francesco@dolcini.it/
> >  - no changes
> > v1: https://lore.kernel.org/all/20250218165633.106867-2-francesco@dolcini.it/
> > ---
> >  .../devicetree/bindings/hwmon/ti,amc6821.yaml      | 14 +++++++++++++-
> >  1 file changed, 13 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/ti,amc6821.yaml b/Documentation/devicetree/bindings/hwmon/ti,amc6821.yaml
> > index 5d33f1a23d03..94aca9c378e6 100644
> > --- a/Documentation/devicetree/bindings/hwmon/ti,amc6821.yaml
> > +++ b/Documentation/devicetree/bindings/hwmon/ti,amc6821.yaml
> > @@ -28,6 +28,13 @@ properties:
> >    i2c-mux:
> >      type: object
> >  
> > +  fan:
> > +    $ref: fan-common.yaml#
> > +    unevaluatedProperties: false
> 
> Why do you need the child, instead of referencing fan-common in the top
> level?

Because shockingly a fan controller and a fan are 2 different pieces of 
h/w. It took *years* for this advancement to come to fruition.

Rob